1. Field of the Invention
The present invention relates to control of earth working implements, such as road graders, and in particular, to improvements in hydraulic control systems therefore.
2. Prior Art
Hydraulic control systems for road graders have long been known and used extensively. Usually of course these are double acting hydraulic cylinders with one positioned on each side of the road grader frame, that in turn control the depth, and also the angle or slope of the circle frame that supports the common earth working blade. Hydraulic cylinders are difficult to control for finish work, in particular when automatic depth controls are being utilized, any changes in depth usually results in some change in the slope of the earth working blade as well, thereby minimizing the preciseness of operation of the unit.